NbS Triple Win Toolkit: Economics and Finance 54 a specific location, ecosystem or geography. This contrasts with the large-scale studies which synthesise data from studies across a variety of geographical regions, ecosystems and NbS interventions to estimatethe value of ecosystem services arising from several land use scenarios. Large-scale studies, whilst promoting the economic case for nature, are not always indicative of the realities of conducting NbS projects on-the-ground in ODA-specific contexts. Similar approaches are unable to fully capture socio-political, geographical and ecological variation which drive local-level project costs and variations between countries and biomes. It is assumed that benefits will flow if the appropriate costs are paid and don’t capture the important institutional, governance and local barriers which likely influence the investment decision for such projects and how well they function in practice. Such studies should be viewed as useful in directing the strategic case for NbS as a tool for resolving societal problems on a global scale, rather than instrumental in guiding individual investment decisions. The research questions typically addressed are related to making the case for nature in an economic context and lay the foundation for local research and detailed analysis. Similarly, local-scale analysis is useful in evidencing specific local examples of successful project implementation and delivery ofbenefits, as well as key trade-offs and uncertainties. Case studyresults, however, are difficult to extrapolate into different contexts, geographies and socio-economic scenarios. The combined suite of models and local projects therefore serves as an evidence base which highlights the potential returns from nature and where these have been, or are proposed to be, achieved in practice. The Economic Case for NbS The case studies which passed selection criteria were reviewed for benefit-cost ratio information (see Methods). Along with key literature reviewing the cost-effectiveness of various NbS approaches, an evidence base for the cost-effectiveness of NbS was developed.The tables below reflect this evidence base for the focal areasdefined in the initial case study search. Table 1 presents marineand coastal evidence, and Table 2 presents terrestrial evidence.There were too few urban cases to present as a standalone table. Six intervention types were selected for further discussion by selecting those interventions with at least 20 instances in the Database of Case Studies that were also found in the evidence base below. It does not necessarily follow that these six are the most effective or cost-effective NbS; simply that there is a stronger evidence base behind them for additional consideration and discussion. Several of the interventions listed below relate to reforestation, afforestation, and agroforestry.These often seem like cost-effective solutions with relatively short timescales for benefits. However, there may be an overemphasis on such interventions when there are other pristine ecosystems to protect and other systems which may provide equivalent or even higher carbon and greenhouse gas (GHG) sequestration rates – such as grasslands or peatlands. These do not, therefore, make up a set of recommendations, but rather useful examples to consider additional factors, trade-offs, or conditions which could impact the effectiveness of a given intervention.